content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ----------------------------------------
   * DefaultBoxAndWhiskerCategoryDataset.java
   * ----------------------------------------
   * (C) Copyright 2003-2012, by David Browning and Contributors.
   *
   * Original Author:  David Browning (for Australian Institute of Marine
   *                   Science);
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * Changes
   * -------
   * 05-Aug-2003 : Version 1, contributed by David Browning (DG);
   * 27-Aug-2003 : Moved from org.jfree.data --> org.jfree.data.statistics (DG);
   * 12-Nov-2003 : Changed 'data' from private to protected and added a new 'add'
   *               method as proposed by Tim Bardzil.  Also removed old code (DG);
   * 01-Mar-2004 : Added equals() method (DG);
   * 18-Nov-2004 : Updates for changes in RangeInfo interface (DG);
   * 11-Jan-2005 : Removed deprecated code in preparation for the 1.0.0
   *               release (DG);
   * ------------- JFREECHART 1.0.x ---------------------------------------------
   * 02-Feb-2007 : Removed author tags from all over JFreeChart sources (DG);
   * 17-Apr-2007 : Fixed bug 1701822 (DG);
   * 13-Jun-2007 : Fixed error in previous patch (DG);
   * 28-Sep-2007 : Fixed cloning bug (DG);
   * 02-Oct-2007 : Fixed bug in updating cached bounds (DG);
   * 03-Oct-2007 : Fixed another bug in updating cached bounds, added removal
   *               methods (DG);
   * 17-Jun-2012 : Removed JCommon dependencies (DG);
   *
   */
  
  package org.jfree.data.statistics;
  
  import java.util.List;
  
  import org.jfree.chart.util.ObjectUtilities;
  import org.jfree.chart.util.PublicCloneable;
  import org.jfree.data.KeyedObjects2D;
  import org.jfree.data.Range;
  import org.jfree.data.RangeInfo;
  import org.jfree.data.general.AbstractDataset;
  import org.jfree.data.general.DatasetChangeEvent;
  
  /**
   * A convenience class that provides a default implementation of the
   * {@link BoxAndWhiskerCategoryDataset} interface.
   */
  public class DefaultBoxAndWhiskerCategoryDataset extends AbstractDataset
          implements BoxAndWhiskerCategoryDataset, RangeInfo, PublicCloneable {
  
      /** Storage for the data. */
      protected KeyedObjects2D data;
  
      /** The minimum range value. */
      private double minimumRangeValue;
  
      /** The row index for the cell that the minimum range value comes from. */
      private int minimumRangeValueRow;
  
      /**
       * The column index for the cell that the minimum range value comes from.
       */
      private int minimumRangeValueColumn;
  
      /** The maximum range value. */
      private double maximumRangeValue;
  
      /** The row index for the cell that the maximum range value comes from. */
      private int maximumRangeValueRow;
  
      /**
       * The column index for the cell that the maximum range value comes from.
       */
      private int maximumRangeValueColumn;
  
      /**
       * Creates a new dataset.
       */
      public DefaultBoxAndWhiskerCategoryDataset() {
          this.data = new KeyedObjects2D();
          this.minimumRangeValue = Double.NaN;
          this.minimumRangeValueRow = -1;
          this.minimumRangeValueColumn = -1;
          this.maximumRangeValue = Double.NaN;
          this.maximumRangeValueRow = -1;
          this.maximumRangeValueColumn = -1;
      }
  
      /**
       * Adds a list of values relating to one box-and-whisker entity to the
       * table.  The various median values are calculated.
       *
       * @param list  a collection of values from which the various medians will
       *              be calculated.
       * @param rowKey  the row key (<code>null</code> not permitted).
       * @param columnKey  the column key (<code>null</code> not permitted).
       *
       * @see #add(BoxAndWhiskerItem, Comparable, Comparable)
       */
      public void add(List<Number> list, Comparable rowKey, Comparable columnKey) {
          BoxAndWhiskerItem item = BoxAndWhiskerCalculator
                  .calculateBoxAndWhiskerStatistics(list);
          add(item, rowKey, columnKey);
      }
  
      /**
       * Adds a list of values relating to one Box and Whisker entity to the
       * table.  The various median values are calculated.
       *
       * @param item  a box and whisker item (<code>null</code> not permitted).
       * @param rowKey  the row key (<code>null</code> not permitted).
       * @param columnKey  the column key (<code>null</code> not permitted).
       *
       * @see #add(List, Comparable, Comparable)
       */
      public void add(BoxAndWhiskerItem item, Comparable rowKey,
              Comparable columnKey) {
  
          this.data.addObject(item, rowKey, columnKey);
  
          // update cached min and max values
          int r = this.data.getRowIndex(rowKey);
          int c = this.data.getColumnIndex(columnKey);
          if ((this.maximumRangeValueRow == r && this.maximumRangeValueColumn
                  == c) || (this.minimumRangeValueRow == r
                  && this.minimumRangeValueColumn == c))  {
              updateBounds();
          }
          else {
  
              double minval = Double.NaN;
              if (item.getMinOutlier() != null) {
                  minval = item.getMinOutlier().doubleValue();
              }
              double maxval = Double.NaN;
              if (item.getMaxOutlier() != null) {
                  maxval = item.getMaxOutlier().doubleValue();
              }
  
              if (Double.isNaN(this.maximumRangeValue)) {
                  this.maximumRangeValue = maxval;
                  this.maximumRangeValueRow = r;
                  this.maximumRangeValueColumn = c;
              }
              else if (maxval > this.maximumRangeValue) {
                  this.maximumRangeValue = maxval;
                  this.maximumRangeValueRow = r;
                  this.maximumRangeValueColumn = c;
              }
  
              if (Double.isNaN(this.minimumRangeValue)) {
                  this.minimumRangeValue = minval;
                  this.minimumRangeValueRow = r;
                  this.minimumRangeValueColumn = c;
              }
              else if (minval < this.minimumRangeValue) {
                  this.minimumRangeValue = minval;
                  this.minimumRangeValueRow = r;
                  this.minimumRangeValueColumn = c;
              }
          }
  
          fireDatasetChanged();
  
      }
  
      /**
       * Removes an item from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @param rowKey  the row key (<code>null</code> not permitted).
       * @param columnKey  the column key (<code>null</code> not permitted).
       *
       * @see #add(BoxAndWhiskerItem, Comparable, Comparable)
       *
       * @since 1.0.7
       */
      public void remove(Comparable rowKey, Comparable columnKey) {
          // defer null argument checks
          int r = getRowIndex(rowKey);
          int c = getColumnIndex(columnKey);
          this.data.removeObject(rowKey, columnKey);
  
          // if this cell held a maximum and/or minimum value, we'll need to
          // update the cached bounds...
          if ((this.maximumRangeValueRow == r && this.maximumRangeValueColumn
                  == c) || (this.minimumRangeValueRow == r
                  && this.minimumRangeValueColumn == c))  {
              updateBounds();
          }
  
          fireDatasetChanged();
      }
  
      /**
       * Removes a row from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @param rowIndex  the row index.
       *
       * @see #removeColumn(int)
       *
       * @since 1.0.7
       */
      public void removeRow(int rowIndex) {
          this.data.removeRow(rowIndex);
          updateBounds();
          fireDatasetChanged();
      }
  
      /**
       * Removes a row from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @param rowKey  the row key.
       *
       * @see #removeColumn(Comparable)
       *
       * @since 1.0.7
       */
      public void removeRow(Comparable rowKey) {
          this.data.removeRow(rowKey);
          updateBounds();
          fireDatasetChanged();
      }
  
      /**
       * Removes a column from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @param columnIndex  the column index.
       *
       * @see #removeRow(int)
       *
       * @since 1.0.7
       */
      public void removeColumn(int columnIndex) {
          this.data.removeColumn(columnIndex);
          updateBounds();
          fireDatasetChanged();
      }
  
      /**
       * Removes a column from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @param columnKey  the column key.
       *
       * @see #removeRow(Comparable)
       *
       * @since 1.0.7
       */
      public void removeColumn(Comparable columnKey) {
          this.data.removeColumn(columnKey);
          updateBounds();
          fireDatasetChanged();
      }
  
      /**
       * Clears all data from the dataset and sends a {@link DatasetChangeEvent}
       * to all registered listeners.
       *
       * @since 1.0.7
       */
      public void clear() {
          this.data.clear();
          updateBounds();
          fireDatasetChanged();
      }
  
      /**
       * Return an item from within the dataset.
       *
       * @param row  the row index.
       * @param column  the column index.
       *
       * @return The item.
       */
      public BoxAndWhiskerItem getItem(int row, int column) {
          return (BoxAndWhiskerItem) this.data.getObject(row, column);
      }
  
      /**
       * Returns the value for an item.
       *
       * @param row  the row index.
       * @param column  the column index.
       *
       * @return The value.
       *
       * @see #getMedianValue(int, int)
       * @see #getValue(Comparable, Comparable)
       */
      @Override
      public Number getValue(int row, int column) {
          return getMedianValue(row, column);
      }
  
      /**
       * Returns the value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the columnKey.
       *
       * @return The value.
       *
       * @see #getMedianValue(Comparable, Comparable)
       * @see #getValue(int, int)
       */
      @Override
      public Number getValue(Comparable rowKey, Comparable columnKey) {
          return getMedianValue(rowKey, columnKey);
      }
  
      /**
       * Returns the mean value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The mean value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMeanValue(int row, int column) {
  
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(row,
                  column);
          if (item != null) {
              result = item.getMean();
          }
          return result;
  
      }
  
      /**
       * Returns the mean value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The mean value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMeanValue(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMean();
          }
          return result;
      }
  
      /**
       * Returns the median value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The median value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMedianValue(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(row,
                  column);
          if (item != null) {
              result = item.getMedian();
          }
          return result;
      }
  
      /**
       * Returns the median value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the columnKey.
       *
       * @return The median value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMedianValue(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMedian();
          }
          return result;
      }
  
      /**
       * Returns the first quartile value.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The first quartile value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getQ1Value(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getQ1();
          }
          return result;
      }
  
      /**
       * Returns the first quartile value.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The first quartile value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getQ1Value(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getQ1();
          }
          return result;
      }
  
      /**
       * Returns the third quartile value.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The third quartile value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getQ3Value(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getQ3();
          }
          return result;
      }
  
      /**
       * Returns the third quartile value.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The third quartile value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getQ3Value(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getQ3();
          }
          return result;
      }
  
      /**
       * Returns the column index for a given key.
       *
       * @param key  the column key (<code>null</code> not permitted).
       *
       * @return The column index.
       *
       * @see #getColumnKey(int)
       */
      @Override
      public int getColumnIndex(Comparable key) {
          return this.data.getColumnIndex(key);
      }
  
      /**
       * Returns a column key.
       *
       * @param column  the column index (zero-based).
       *
       * @return The column key.
       *
       * @see #getColumnIndex(Comparable)
       */
      @Override
      public Comparable getColumnKey(int column) {
          return this.data.getColumnKey(column);
      }
  
      /**
       * Returns the column keys.
       *
       * @return The keys.
       *
       * @see #getRowKeys()
       */
      @Override
      public List<Comparable> getColumnKeys() {
          return this.data.getColumnKeys();
      }
  
      /**
       * Returns the row index for a given key.
       *
       * @param key  the row key (<code>null</code> not permitted).
       *
       * @return The row index.
       *
       * @see #getRowKey(int)
       */
      @Override
      public int getRowIndex(Comparable key) {
          // defer null argument check
          return this.data.getRowIndex(key);
      }
  
      /**
       * Returns a row key.
       *
       * @param row  the row index (zero-based).
       *
       * @return The row key.
       *
       * @see #getRowIndex(Comparable)
       */
      @Override
      public Comparable getRowKey(int row) {
          return this.data.getRowKey(row);
      }
  
      /**
       * Returns the row keys.
       *
       * @return The keys.
       *
       * @see #getColumnKeys()
       */
      @Override
      public List<Comparable> getRowKeys() {
          return this.data.getRowKeys();
      }
  
      /**
       * Returns the number of rows in the table.
       *
       * @return The row count.
       *
       * @see #getColumnCount()
       */
      @Override
      public int getRowCount() {
          return this.data.getRowCount();
      }
  
      /**
       * Returns the number of columns in the table.
       *
       * @return The column count.
       *
       * @see #getRowCount()
       */
      @Override
      public int getColumnCount() {
          return this.data.getColumnCount();
      }
  
      /**
       * Returns the minimum y-value in the dataset.
       *
       * @param includeInterval  a flag that determines whether or not the
       *                         y-interval is taken into account.
       *
       * @return The minimum value.
       *
       * @see #getRangeUpperBound(boolean)
       */
      @Override
      public double getRangeLowerBound(boolean includeInterval) {
          return this.minimumRangeValue;
      }
  
      /**
       * Returns the maximum y-value in the dataset.
       *
       * @param includeInterval  a flag that determines whether or not the
       *                         y-interval is taken into account.
       *
       * @return The maximum value.
       *
       * @see #getRangeLowerBound(boolean)
       */
      @Override
      public double getRangeUpperBound(boolean includeInterval) {
          return this.maximumRangeValue;
      }
  
      /**
       * Returns the range of the values in this dataset's range.
       *
       * @param includeInterval  a flag that determines whether or not the
       *                         y-interval is taken into account.
       *
       * @return The range.
       */
      @Override
      public Range getRangeBounds(boolean includeInterval) {
          return new Range(this.minimumRangeValue, this.maximumRangeValue);
      }
  
      /**
       * Returns the minimum regular (non outlier) value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The minimum regular value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMinRegularValue(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getMinRegularValue();
          }
          return result;
      }
  
      /**
       * Returns the minimum regular (non outlier) value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The minimum regular value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMinRegularValue(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMinRegularValue();
          }
          return result;
      }
  
      /**
       * Returns the maximum regular (non outlier) value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The maximum regular value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMaxRegularValue(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getMaxRegularValue();
          }
          return result;
      }
  
      /**
       * Returns the maximum regular (non outlier) value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The maximum regular value.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMaxRegularValue(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMaxRegularValue();
          }
          return result;
      }
  
      /**
       * Returns the minimum outlier (non farout) value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The minimum outlier.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMinOutlier(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getMinOutlier();
          }
          return result;
      }
  
      /**
       * Returns the minimum outlier (non farout) value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The minimum outlier.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMinOutlier(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMinOutlier();
          }
          return result;
      }
  
      /**
       * Returns the maximum outlier (non farout) value for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return The maximum outlier.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMaxOutlier(int row, int column) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getMaxOutlier();
          }
          return result;
      }
  
      /**
       * Returns the maximum outlier (non farout) value for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return The maximum outlier.
       *
       * @see #getItem(int, int)
       */
      @Override
      public Number getMaxOutlier(Comparable rowKey, Comparable columnKey) {
          Number result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getMaxOutlier();
          }
          return result;
      }
  
      /**
       * Returns a list of outlier values for an item.
       *
       * @param row  the row index (zero-based).
       * @param column  the column index (zero-based).
       *
       * @return A list of outlier values.
       *
       * @see #getItem(int, int)
       */
      @Override
      public List<Number> getOutliers(int row, int column) {
          List<Number> result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  row, column);
          if (item != null) {
              result = item.getOutliers();
          }
          return result;
      }
  
      /**
       * Returns a list of outlier values for an item.
       *
       * @param rowKey  the row key.
       * @param columnKey  the column key.
       *
       * @return A list of outlier values.
       *
       * @see #getItem(int, int)
       */
      @Override
      public List<Number> getOutliers(Comparable rowKey, Comparable columnKey) {
          List<Number> result = null;
          BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                  rowKey, columnKey);
          if (item != null) {
              result = item.getOutliers();
          }
          return result;
      }
  
      /**
       * Resets the cached bounds, by iterating over the entire dataset to find
       * the current bounds.
       */
      private void updateBounds() {
          this.minimumRangeValue = Double.NaN;
          this.minimumRangeValueRow = -1;
          this.minimumRangeValueColumn = -1;
          this.maximumRangeValue = Double.NaN;
          this.maximumRangeValueRow = -1;
          this.maximumRangeValueColumn = -1;
          int rowCount = getRowCount();
          int columnCount = getColumnCount();
          for (int r = 0; r < rowCount; r++) {
              for (int c = 0; c < columnCount; c++) {
                  BoxAndWhiskerItem item = getItem(r, c);
                  if (item != null) {
                      Number min = item.getMinOutlier();
                      if (min != null) {
                          double minv = min.doubleValue();
                          if (!Double.isNaN(minv)) {
                              if (minv < this.minimumRangeValue || Double.isNaN(
                                      this.minimumRangeValue)) {
                                  this.minimumRangeValue = minv;
                                  this.minimumRangeValueRow = r;
                                  this.minimumRangeValueColumn = c;
                              }
                          }
                      }
                      Number max = item.getMaxOutlier();
                      if (max != null) {
                          double maxv = max.doubleValue();
                          if (!Double.isNaN(maxv)) {
                              if (maxv > this.maximumRangeValue || Double.isNaN(
                                      this.maximumRangeValue)) {
                                  this.maximumRangeValue = maxv;
                                  this.maximumRangeValueRow = r;
                                  this.maximumRangeValueColumn = c;
                              }
                          }
                      }
                  }
              }
          }
      }
  
      /**
       * Tests this dataset for equality with an arbitrary object.
       *
       * @param obj  the object to test against (<code>null</code> permitted).
       *
       * @return A boolean.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (obj instanceof DefaultBoxAndWhiskerCategoryDataset) {
              DefaultBoxAndWhiskerCategoryDataset dataset
                      = (DefaultBoxAndWhiskerCategoryDataset) obj;
              return ObjectUtilities.equal(this.data, dataset.data);
          }
          return false;
      }
  
      /**
       * Returns a clone of this dataset.
       *
       * @return A clone.
       *
       * @throws CloneNotSupportedException if cloning is not possible.
       */
      @Override
      public Object clone() throws CloneNotSupportedException {
          DefaultBoxAndWhiskerCategoryDataset clone
                  = (DefaultBoxAndWhiskerCategoryDataset) super.clone();
          clone.data = (KeyedObjects2D) this.data.clone();
          return clone;
      }
  
  }
  